Frog Out of Water

Decreased water levels at Colorado Dam threaten endangered species

The delicate balance between human-driven development and wildlife conservation came to a head last month when the extraction of the Colorado Avenue Dam caused an unexpected drop in water levels in the adjacent marsh, threatening the habitat of the endangered Oregon spotted frog.

"When they pulled the dam out, it pulled the water out of the marsh," explains U.S. Fish and Wildlife biologist Jennifer O'Reilly. "The breeding area was dewatered."

O'Reilly was among the first to discover the dangerously low water levels on May 11 and says that, despite rumors that dried out egg masses had been discovered, "there was no carnage."

"It wasn't a full-on kill, but it was concerning," O'Reilly explains. "I got Bend Parks and Rec and their engineers on the phone, and said, 'You have to get the water level up in the marsh.'"

Bend Park and Recreation District was quick to respond, she says, suspending work on the project while they worked to sand bag to restore water levels.

"It was like a perfect storm," explains Chelsea Schneider, project manager for the Bend Whitewater Park project. "The river flows, which are controlled by Bureau of Reclamation, were lowered at the same time we were removing dam."

She says that as soon as U.S. Fish and Wildlife (USFW) notified BPRD, they raised the 10 pneumatic panels that control channel flows, which allowed water to return to the marsh. The Parks department has no control over or prior knowledge of when or how much the Bureau will adjust flows, Schneider explains, and can only see what the hydrograph shows is currently coming through.

"This is a once in a construction project event," Schnieder explains. "There is no opportunity for that particular series of events to happen again."

Still, since the dewatering, the water levels in the marsh are being checked every two hours by Hamilton Construction. Once BPRD takes over operation of the project, Schneider says it will use a computerized system to monitor flows, and the pneumatic panels—essentially walls to hold back water powered by a large airbag-like balloons—to adjust as needed.

And while no one anticipated that the dam removal would cause such a serious decrease in water levels, O'Reilly says the incident has a silver lining in that it prompted USFW and BPRD to re-evaluate how they approach projects that interface with protected wildlife habitat.

"This is the first project that we've encountered the Oregon spotted frog," Schneider says, noting that the species was listed as endangered as BPRD was going through the permitting process for the whitewater project. "We look forward to working closely with U.S. Fish and Wildlife on future projects."

As far as O'Reilly is aware, the Oregon spotted frog is the only water-based listed species in the local area. Further out, bull trout can be found in Odell Lake, and spotted owls make their home in nearby forests.

"It's a newly listed species, most people aren't used to having a listed species in the water," she says. "It's a new way of doing business. I hope it woke people up."

Because the Oregon spotted frog is federally protected, any threats to its welbeing have to be reported to USFW law enforcement. However, O'Reilly says she doesn't expect them to press charges since it was an accident. Under the Endangered Species Act, causing harm to an endangered species is a felony, punishable by fines of up to $200,000 and a year in prison.

"They're always notified if something happens," O'Reilly explains. "But we didn't see the need to bring them down as heavies to enforce because of the cooperation we received from Bend Parks and Rec."

The Oregon spotted frog is especially vulnerable to changes in water levels because, unlike some other amphibians that only breed in water, they live in the water fulltime. And while fish can swim away when water levels start to drop, O'Reilly says the frogs and tadpoles can be easily trapped on a mudflat.

The incident has prompted the projects partners to take a closer look at how they mitigate negative impacts on Oregon spotted frog through the remainder of the construction process as well as future operations.

"I'm working with Army Corps of Engineers," O'Reilly says, "to look at the operation and maintenance of that facility and how it may or may not affect water levels."

When the Army Corps of Engineers issued a permit to Bend Park and Rec for the project, it outlined specific measures that needed to be taken to avoid causing harm to the endangered species. Among those, Schneider says, were maintaining water levels while frogs were in the egg stage and acoustic monitoring to ensure the species was not disturbed by noisy equipment during certain phases of development. She notes that despite the unexpected incident, construction is still on track, with the whitewater park scheduled to open this fall.

While unfortunate, O'Reilly says the dewatering could not have been anticipated. In many ways, it was a learning experience.

"It was a mistake, it was unanticipated," she says. "Folks learn the hard way—we all did."